||
Morykwas and colleagues tested in pigs whether controlled suction delivered through sealed open‑cell foam improves wound perfusion, granulation, bacterial clearance and flap survival.
Four porcine experiments of 5 to 10 animals each, Bowman Gray School of Medicine.
Methods
- Model
- Pig wounds
- Controls: saline gauze (granulation), foam without suction (bacterial clearance), no suction (flaps)
- Intervention
- Continuous 125 mmHg subatmospheric pressure via open‑cell foam dressing
- Intermittent 125 mmHg (5 min on, 2 min off) via open‑cell foam dressing
- Assays
- Laser Doppler blood flow in wound and adjacent tissue (5 pigs)
- Granulation tissue formation rate (10 pigs)
- Bacterial counts in infected wounds (5 pigs)
- Random‑pattern flap survival (5 pigs)
Key Findings
- Blood flow in subcutaneous tissue and muscle peaked at four times baseline at 125 mmHg of suction and fell below baseline at 400 mmHg or more.
- Continuous suction raised the rate of granulation tissue formation by a mean 63.3% ± 26.1% over gauze controls (p ≤ 0.01).
- Intermittent suction (5 minutes on, 2 minutes off) raised the granulation rate by a mean 103.4% ± 35.3% over controls in all 5 animals (p ≤ 0.01).
- Bacterial counts in infected wounds fell below 10⁵ organisms per gram between days 4 and 5 with suction, vs a mean of 11 days in control wounds.
- Random‑pattern flaps treated with suction both before and after surgery survived 72.2% vs 51.2% for untreated controls (p ≤ 0.01).
Board pearl
The V.A.C. transmits 125 mmHg below ambient pressure to the wound through open‑cell foam sealed beneath an adhesive drape.
Authors' conclusion
We determined that the application of controlled subatmospheric pressure creates an environment that promotes wound healing.